Only exceptions are two geographically-distant pastoralist groups- Toda & Gujjar. By performing local ancestry inference, we find significant enrichment for Steppe pastoralist ancestry around the LCT locus in these two geographically-distant pastoralist groups, indicative of strong recent selection.

Interestingly, unlike in other worldwide populations, the LP prevalence is almost entirely explained by Steppe ancestry—not selection––in most contemporary South Asians.

Ancient DNA evidence indicates that this allele was introduced into South Asia during the historical to early medieval periods (756 BCE–52 CE), through Steppe pastoralist–related gene flow.

We find that the Eurasian variant, −13.910:C>T, is widespread across South Asia, with regional heterogeneity. The frequency ranges from 10%–15%, except in two pastoralist groups: the Gujjar (Pakistan) & Toda (South India), where frequencies reach ~65%—similar to Northern Europeans.